This invention relates to a relay including a control circuit which via a movement creating or actuating arm and a transmission mechanism, activates a contact means in order to switch on or switch off a main circuit. The actuating arm comprises two elongated parallel parts which are separated by a thermally insulated layer. The two parallel parts each have a first end fastened to a holder or base support. The two parallel parts each have a second end fixed to each other, forming a movable end of the arm. One or both parallel parts of the arm are provided with a heat creating or producing element. The actuating arm, attached at one end and movable at the other end, together with the heat producing element, constitutes the first part of the control circuit or relay. When a control current flows through the heat producing element, one of the two parallel parts of the arm is heated thereby causing a movement of the movable end of the arm to thereby activate the control means.
A device of the abovementioned type is previously known, see EP 403453. The device shown in this publication has however certain shortcomings since the transmission mechanism requires relatively large movements of the arm in order to work properly which means that the device achieves a rather large height. At the same time the transmission mechanism and the position of the contact means combine so that the complete arrangement further results in a rather large extension in the length direction of the arm.
The purpose of this invention is to achieve a relay device of the type described above but with a more compact layout than previously known. The device is also suitable for mass production.